FIG. 1 illustrates a typical spin logic device 100 with stacking of magnets above a spin channel. To illustrate the deficiencies of device 100, a brief overview of forming device 100 is described. Device 100 is formed by depositing a metal (e.g., Cu) for providing a ground supply and then depositing a layer of oxide over the metal. The metal for the ground supply forms the bottom of device 100. The oxide is then etched to form a via hole which is then filled with metal to form a Via. A metal layer (e.g. layer of Cu) is again deposited to form a Spin Channel. Parts of the Spin Channel are then etched to form barriers between the Spin Channel. Oxide is then deposited into these barriers. Followed by oxide deposition, a magnet layer is deposited and selectively etched to form input and output magnets (e.g., Magnet on the left and Magnet on the right, respectively). These magnets are in direct contact with the Spin Channel. Metal (e.g., Cu) is then deposited on the etched magnets to provide supply contacts followed by a layer of deposition of a metal layer (e.g., layer of Cu) for providing power supply. The metal for power supply forms the top of device 100.
While spin logic and spin memory can enable a new class of logic devices and architectures for beyond Complementary Metal Oxide Semiconductor (CMOS) computing, they suffer from certain deficiencies. For example, existing spin devices such as device 100 suffer from low speed and require high current operation due to magnetic switching speed being limited by the strength of magnetic anisotropy (Hk) and low polarization of spin injection from the magnets into the spin channel.
The manufacturing of spin device such as device 100 is expensive. For example, forming the oxide barriers between the Spin Channel is an extra etching step. Furthermore, if the barrier is raised to form a partially thin channel portion above the oxide barrier for coupling the magnets, more complicated processes of etching and deposition are needed.
The manufacturing of spin device such as device 100 is also challenging. For example, intermixing of magnetic elements (such as Co, Fe, and Ni) into the Spin Channel produces local spin scattering in the Spin Channel. Spin scattering lowers the performance of device 100 because it lowers the degree of spin polarization of the current injected into the spin channel compared to the current in the ferromagnet. Also, traditional material stack used for manufacturing spin devices are incompatible to accommodate certain magnetic materials such as Heusler alloys.